Space Exploration for Kids

About Venus

Venus was known to the ancients as one of the brightest objects in the sky, right behind the Sun and the Moon. Depending on when it appeared, it was known as the morning star or the evening star. When telescopic observations of the planets began, it was quickly noted that Venus obviously had a considerable atmosphere, since it was entirely covered in clouds. Associating clouds with water, visions of a world covered with a global ocean filled the imaginations of early speculators.

When spectroscopes were finally attached to telescopes, astronomers peered at Venus, expecting to find strong lines indicative of water. Surprisingly, there was none. Instead, they found strong indications of carbon dioxide. The visions of a planet-wide ocean evaporated, replaced by the idea of a dry, warm world surrounded by clouds of dust and formaldehyde.

Just how hot and dry was yet to be seen. Further observations revealed that there was a lot of carbon dioxide, and that the temperatures were even higher than originally anticipated. Ultimately, Venus was found to literally be the Hades of the heavens, roasting at around 460° C, beneath a crushing atmosphere that weighs down on the surface with 92 times the sea level pressure on Earth. And the clouds turned out to be composed of sulfuric acid.

Radar imaging of the surface has revealed that Venus is covered in volcanoes. While there is no direct evidence of current eruption activity, there is some indirect evidence in the form of strong variations in the amount of sulfur dioxide—a common volcanic gas—detected in the atmosphere. Lightning has been detected, and one possibility is that at least some of it is related to volcanic plumes, while the rest is mostly cloud-to-cloud discharges in the upper atmosphere.

Earth's crust is composed of individual plates, riding on top of the mantle underneath, which are in constant slow motion, grinding against each other and producing quakes and volcanoes. However, Venus does not appear to have a system of plate tectonics; rather, its crust is a single unit—a shell, so to speak—surrounding the planet like the rind of an orange. Therefore, the mechanism for volcanism must be different. The most popular explanation for Venus' lack of tectonic plates is its lack of water.

There are almost a thousand large impact craters on the surface of Venus. Without rainfall or other processes to erode them, craters tend to remain pretty much unchanged over long periods of time. There are no small craters; because of the thick atmosphere, meteors below a certain size simply do not make it all the way to the surface.

Although there is no rainfall on the surface of Venus, there is virga—of sulfuric acid. The thick clouds rain H2SO4 from high in the atmosphere, but it evaporates at around 25 km, well before it can get anywhere near the scorching surface.

Venus does not have any natural satellites.

Observation from Earth

Because Venus is closer to the Sun than Earth, it is only visible in the evening and morning, with its greatest angular separation from the Sun being 47.8°. Because of its greater reflectivity and distance from the Sun than Mercury, it has always been easier to study. For example, Galileo was able to quickly determine that Venus showed phases as it revolved around the Sun, whereas he was unable to see phases on Mercury.

Like Mercury, the ancients believed for a long time that Venus was actually two distinct bodies, one visible in the morning and the other at evening. It is Pythagoras who is usually credited with discovering that it was really one object. Nevertheless, he clung to the belief that Venus—and everything else in the sky—revolved around the Earth. Interestingly, it was Galileo's discovery of phases that was some of the first solid evidence that it actually revolved around the Sun.

The ancient Hindus called Venus Shukra.

Exploration of Venus

Surface of Venus seen from Venera 13

Venus has been visited extensively by spacecraft from the former Soviet Union, the United States and the European Union. Venera 1 was the first probe sent to any planet in our solar system. Unfortunately, it failed a week after launch. The American Mariner 2 became the first successful interplanetary mission, flying past Venus in December of 1962. Three and a half years later, in March of 1966, the Soviet Venera 3 became the first man-made object to touch the surface of another planet.

Since then there have been a number of flybys, landers and orbiters. The American Magellan mapped nearly the entire surface using radar to penetrate the thick clouds. The Soviets successfully inserted a couple of balloons into the upper Venusian atmosphere, which each lasted almost two days at an altitude of 53 km, where the temperature and pressure are similar to those on the surface of the Earth.

Ironically, one of the advantages of the tremendously dense atmosphere is that Venus probes do not need parachutes in order to land gently enough to survive. Air friction and braking is sufficient for a relatively soft landing. At least four Soviet Venera probes dumped their chutes at 50 km altitude, then went on to return pictures and scientific data from the surface.

A number of the Venus probes were actually flybys on the way to other destinations, such as Vega on its way to Halley's Comet (which dropped the aforementioned balloons), Galileo on its way to Jupiter, Cassini on its way to Saturn and MESSENGER on its way to Mercury.

In November of 2005, the European Space Agency launched the Venus Express probe, which spent from April of 2006 to December of 2014 in a polar orbit around the planet, performing a number of different observations of the surface, atmosphere and surrounding environment. After it exhausted its propellant, it was no longer able to orient its antenna to point to Earth. Eventually, its orbit decayed (it was passing through the upper trace layers of atmosphere) and it fell into the atmosphere and burned up.

In May of 2010, the Japanese space agency launched Akatsuki, intended to orbit and explore Venus. On December 7 of the same year, it arrived at Venus, but due to a failure in its rocket motor system, it did not successfully enter orbit. After circling the sun for five years, in December of 2015 engineers were able to use the attitude control thrusters to place it into an alternate elliptical orbit around the planet. Akatsuki is also known as Venus Climate Orbiter, and is studying stratification of the atmosphere, atmospheric dynamics and cloud physics. It is currently in an extended observation phase of its mission.

Venus is Hell?

Intriguingly, the extreme heat, crushingly dense atmosphere, clouds of sulfuric acid and sulfur dioxide immediately bring to mind the Lake of Fire mentioned in Revelation. I used to wonder if this was more than just a coincidence. Today, however, astronomers know of extrasolar planets that make Venus look like a cool paradise. So we probably haven't yet really discovered where the place of eternal judgment lies.

Nevertheless, I still wonder at times if God gave us this planetary neighbor as a “warning”. If the simple thought of experiencing conditions like on Venus gives you the willies, and you are not 100% sure that you will end up going to Heaven instead, do yourself a favor and read the page on Beyond Death.